package com.netty.echo;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

@ChannelHandler.Sharable // 标示一个 ChannelHandler 可以被多个 Channel 安全的共享
public class EchoServerHandler extends ChannelInboundHandlerAdapter {

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		ByteBuf in = (ByteBuf) msg;
		System.out.println("server received: " + in.toString(CharsetUtil.UTF_8));
		ctx.write(in);
	}

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
		// 将未决消息冲刷到远程节点并且关闭channel
		ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
	}

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
		cause.printStackTrace();
		// 打印异堆栈跟踪
		ctx.close();
	}
}
